Complexes of ozone with carbon .pi. systems

Bailey, Philip S.; Ward, James W.; Carter, Thomas P.; Nieh, Edward; Fischer, Charles M.; Khashab, Abdul I. Y.

doi:10.1021/ja00826a028

Cited by 40 publications

(15 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the reaction of ozone with olefins, there is evidence at low temperatures for the formation of a charge transfer complex which subsequently decays into products. 54,55 If in the present case such a charge transfer complex is sufficiently long-lived it could turn more acidic than its parent. As a consequence of this, the rate of reaction could be higher than the one calculated on the basis of the pK a value of the parent.…”

Section: Uracil Thymine and Their Derivativesmentioning

confidence: 82%

Rate constants of ozone reactions with DNA, its constituents and related compounds

Theruvathu

Flyunt

Aravindakumar

et al. 2001

J. Chem. Soc., Perkin Trans. 2

View full text Add to dashboard Cite

Section: Uracil Thymine and Their Derivativesmentioning

confidence: 82%

Rate constants of ozone reactions with DNA, its constituents and related compounds

Theruvathu

Flyunt

Aravindakumar

et al. 2001

J. Chem. Soc., Perkin Trans. 2

View full text Add to dashboard Cite

“…2-methyl-2-butene, 1-methylcyclohexene, and 2-methyl-1-butene (yOH ) 0.93, 0.91, 0.67, respectively) all fit this model as well. cis-and trans-2-butene obviously generate only acetaldehyde; however, ab initio calculations coupled with measurements of the stereoisomers of the carbonyl oxide-aldehyde addition product in some solvents 71,72 suggests that cis-2-butene may generate more anti carbonyl oxide than trans. Thus, while the simplest model predicts 50% for both, this refinement adjusts the OH yield for cis down, and depending on the calculation, trans-up, 42,48 qualitatively explaining the higher OH yield from trans-2-butene (0.64, 0.54, 0.65 10,56,73 ) compared to cis-2-butene (0.41, 0.33, 0.37, 10,56,73 ).…”

Section: Mechanistic Implicationsmentioning

confidence: 99%

OH Radical Formation from the Gas-Phase Reaction of Ozone with Terminal Alkenes and the Relationship between Structure and Mechanism

1999

View full text Add to dashboard Cite

The reactions of ozone with alkenes have been shown recently to lead to the direct production of OH radicals in quantities that vary from 7 to 100% depending on the structure of the alkene. OH radicals are the most important oxidizing species in the lower atmosphere, and the OH−alkene reaction is a large source of new OH radicals, important in urban and rural air during both day and night. Evidence for OH formation comes both from low-pressure direct measurements and from tracer experiments at high pressure. With the goal of measuring OH formation yields with good precision, a small-ratio relative rate technique was developed. This method uses small amounts of fast-reacting aromatics and aliphatic ethers to trace OH formation yields. Here, we report OH formation yields for a series of terminal alkenes reacting with ozone. Measured OH yields were 0.29 ± 0.05, 0.24 ± 0.05, 0.18 ± 0.04, and 0.10 ± 0.03 for 1-butene, 1-pentene, 1-hexene, and 1-octene, respectively. For the methyl-substituted terminal alkenes methyl propene and 2-methyl-1-butene, OH yields were 0.72 ± 0.12 and 0.67 ± 0.12, respectively. The results are discussed both in terms of their atmospheric implications and the relationship between structure and OH formation.

show abstract

“…* Values in parentheses are ozonide yields. 4 Toluene does not complex with ozone in Freon-12 except at lower temperatures.…”

mentioning

confidence: 92%

Stereochemistry of ozonide formation. Effects of complexing agents and rate of warm-up

Bailey¹,

Ferrell²,

Rustaiyan³

et al. 1978

J. Am. Chem. Soc.

Self Cite

View full text Add to dashboard Cite

Data concerning differences in cis-trans ozonide ratios, depending on (1) the presence or absence of complexing agents and (2) a fast or slow warm-up of the ozonolysis reaction mixture, are presented for five different cis-trans olefin pairs. Evidence is discussed which indicates that the carbonyl oxide intermediate is complexed at low temperatures and this either prevents equilibration of syn and anti carbonyl oxide stereoisomers or selectively favors the anti isomer through stronger complexation. The effects are greater the larger the olefinic double bond substituents. truns-1,2-DiisopropyIethylene gives cistrans ozonide ratios of greater than unity under slow warm-up conditions, which is contrary to predictions based on existing stereochemical mechanisms. The first observation of complexes of ozone with carbon a systems was reported from this laboratory in 197 1 .2.3 These complexes involved either aryl substituted or purely aromatic compound^.^ Following our first communication,* similar complexes were claimed for certain aliphatic system^,^,^ although doubt was cast upon the conclusions of Hull et aL5 by the data reported by Alcock and Mile.6In our 1974 paper,4 we made the tentative observation that ozonolyses of cis and trans olefins with complexed ozone afforded cis-trans ozonide ratios which differed from those obtained with "free" ozone. This was confirmed in our most recent communication on the ~u b j e c t ,~ where improved technique and consistent results, using a slow warm-up procedure, were reported. Differences in results with slow and fast warm-ups were first observed by Murray and Hagene8The purpose of the present paper is to describe the experimental details of the findings presented in our 1976 commun i~a t i o n ,~ as well as of some other recent work, and to discuss in greater detail the theoretical implications. Included in this paper are studies with the cis and trans isomers of 2,5-dimethyl-3-hexene (diisopropylethylene), 2,2,5,5-tetramethyl-3-hexene (di-tert-butylethylene), 3-hexene, 2-butene, and 4-methyl-2-pentene (isopropylmethylethylene). In later papers further investigations will be presented, involving additional complexing agents and olefins as well as solvents and reaction conditions. Table I shows the cis-trans ozonide ratios obtained by ozonizing cis-and trans-1,2-diisopropylethylene with and without a complexing agent a t two different temperatures and in two different solvents. It can be seen that the cis-trans ozonide ratios obtained a t -155 O C with the cis isomer differ depending on the presence or absence of a complexing agent.This also appears to be true in two instances with the trans isomer in isopentane solution. However, the results portrayed in Table I1 show that the cis-trans ozonide ratios are the same, within experimental error, whether (1) the ozonolysis is performed with previously complexed ozone, (2) a mixture of the olefin and the complexing agent is ozonized, or (3) the complexing agent is added to the -1 55 O C reaction mixture after ozonolysis of the ole...

show abstract

Complexes of ozone with carbon .pi. systems

Cited by 40 publications

References 0 publications

Rate constants of ozone reactions with DNA, its constituents and related compounds

Rate constants of ozone reactions with DNA, its constituents and related compounds

OH Radical Formation from the Gas-Phase Reaction of Ozone with Terminal Alkenes and the Relationship between Structure and Mechanism

Stereochemistry of ozonide formation. Effects of complexing agents and rate of warm-up

Contact Info

Product

Resources

About